1. Field of the Invention
The present invention relates to a power supply apparatus, and more particularly, to a high voltage power supply apparatus for generating a high voltage signal by using a low voltage signal.
2. Description of the Related Art
An image forming apparatus such as a laser beam printer (LBP) includes a plurality of devices that electronically operate. Examples of the devices may include a device for uniformly charging a surface of a photosensitive drum included in the image forming apparatus, a device for developing an electrostatic latent image formed on the surface of the photosensitive drum, and a device for transferring the developed electrostatic latent image on a printing medium. Although voltages of power supplied to each of the devices may be different from one another, all of the power may have a signal of direct current (DC) high voltage of a predetermined DC voltage or more (e.g., DC voltage of 1000 V). On the other hand, an alternative current (AC) voltage (e.g., AC voltage for family use of 220 Vrms, where ‘rms’ refers to ‘root mean square’) applied to the image forming apparatus is converted into a predetermined DC low voltage signal (e.g., DC voltage of 5 V) and then input to the image forming apparatus, and thus a high voltage power supply apparatus for receiving a low voltage signal to generate a plurality of high voltage signals needs to be installed in the image forming apparatus.
The high voltage power supply apparatus is embodied as a single substrate on which a circuit for receiving a single low voltage signal to generate a plurality of high voltage signals is formed. A plurality of circuit devices are scattered on the substrate according to a designer's plan. Under this environment, there is a limit in minimizing the size of the substrate, and thus it is difficult to satisfy a recent state in which miniaturized products hold a high market share. In a high voltage power supply apparatus, the larger the number of high voltage signals generated using a single signal, the larger the number of circuit devices arranged on the substrate. Accordingly, the larger the number of high voltage signals generated using a single signal, the more difficult to satisfy the recent state.